Static electricity grounding device



Oct. 23, 1956 A. GREENBLATT 9 STATIC ELECTRICITY GROUNDING DEVICE Filed Aug. 18, 1955 INVENTOR. A/berz Greenb/a'zfz v BY 7 9 I Y Afiarley United States Patent 2,7 67,659 STATIC ELECTRICITY GROUNDING DEVICE Albert Greenblatt, Warwick, R. I. Application August 18, 1955, Serial No. 529,237 Claims. (Cl. 103-25) This invention relates to a safety device, and more particularly to an apparatus for preventing fires or explosions resulting from static electricity during handling of gasoline and the like by trucks or trailers.

The object of the invention is to provide an apparatus which will serve to effectively discharge static electricity from gasoline trucks when the trucks are being loaded with the fuel so that there will be no danger of fires, explosions and the like.

Another object of the invention is to provide a static electricity discharge mechanism which includes a plural ity of spring members that are adapted to be driven over and engaged by the lower portion of a fuel truck so that when the spring members are engaged and flexed downwardly, an electrical circuit to a fuel pump will be energized whereby the pump motor will be permitted to pump fuel into the waiting truck so that there will be no danger of the fuel pump operating until the truck is in a position to cause any static electricity thereon to be safely discharged into the ground.

Another object of the invention is to provide a static electricity discharge mechanism which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure l is a top plan view of the static electricity discharge mechanism, constructed according to the present invention, and with parts broken away and in section.

Figure 2 is a sectional view taken on the line 22 of Figure 1.

Figure 3 is a transverse sectional view taken through the apparatus, and showing a gasoline truck in position thereon.

Referring in detail to the drawings, the numeral designates a horizontally disposed plate which can be made of any suitable material, and the plate 10 is adapted to be mounted on a suitable surface 11 of concrete or the like. Spaced from the plate 10 is a horizontally disposed base 12 which has a fuel or gasoline pump 14 extending upwardly therefrom. Positioned below the plate 10 is a housing 15 which has a switch 16 mounted therein. The switch 16 includes a fixed contact 17, and a movable contact 18 is mounted for movement into and out of engagement with the fixed contact 17. The contact 18 is pivotally mounted in the switch 16 by means of a pin 19. A first wire 20 leads from the movable contact 18 to a suitable source of electrical energy. Leading from the fixed contact 17 is a second wire 21 for a purpose to be later described.

There is further provided a motor 22 of conventional construction, and the motor 22 serves to operate a fuel pump whereby fuel can be readily pumped into a waiting truck when desired. A third wire 23 leads from the pump motor 22 to a suitable source of electrical energy, and a fourth wire 24 also leads from the pump motor 22.

The wire 24 is connected to a terminal 25, and a movable contact 26 has one end connected to the terminal 25. A fifth wire 27 leads to a suitable source of electrical energy, and the wire 27 leads to a contact 28 which is adapted to be selectively engaged by the movable contact 26. A coil spring 29 has one end connected to the contact 26.

Also arranged in the fuel pump housing 14 is a solenoid 30 which serves to actuate a core 31, and a link 32 extends from the core 31 to the movable contact 26. The wire 21 is connected to the core 30, and a sixth wire 33 is adapted to lead from the solenoid 30 to a suitable source of electrical energy.

Mounted above th plate 10 is a plurality of spaced parallel spring members 34 which each include an end portion 35 that is secured in place to the plate 10 by means of a suitable securing element such as a bolt or screw 36. Each spring member 34 further includes an offset section 37 and a major curved portion 42. Each curved portion 42 terminates in a flat portion 38 which is slidably mounted in a slot 39 in a bracket 40. The bracket 40 may be secured to the plate 10 by suitable securing elements 41.

The spring members 34 are each provided with a plurality of upstanding knobs or protuberances 43 which are adapted to be engaged by the lower portion such as the rear or front portion of a gasoline truck 44. Thus, an axle housing 46 may engage the curved portions 42 of the spring members 34 as shown in Figure 3 so as to cause thes spring members 34 to flex or bend downwardly. The truck 44 may include the usual tank 45 which is adapted to be filled with fuel such as gasoline.

Extending transversely beneath the offset sections 37 of the spring members 34 is a horizontally disposed bar 47, and a ground rod 48 depends from the bar 47. The rod 48 extends down into the ground so that static electricity from the truck 44 will be readily discharged safely into the ground.

Extending transversely beneath the curved portions 42 of the spring members 34 is a horizontally disposed bar or brace 49, and depending from the brace 49 is a plurality of vertically disposed arms or rods 50. The intermediate rod 50 has its lower end pivotally connected to the movable contact 18 by means of a pivot pin 51. A coil spring 52 may be circumposed on the intermediate rod 50 for normally urging the middle rod 50 to its upward or raised position.

From the foregoing, it is apparent that ther has been provided an apparatus which is especially suitable for use in grounding electricity from gasoline trucks such as the truck 44. In use, the contact 18 is normally out of engagement with the contact 17. Also, the contact 26 is normally out of engagement with the contact 28. The springs 34 are also normally in the position shown in Figure 2. Then, when a truck such as the gasoline truck 44 drives up to be filled with gasoline from the gas pump 14, as at a loading station, the truck drives over the spring members 34 so that a portion of the truck such as the axle housing 46 engages the spring members 34 and biases or flexes them downwardly as shown in Figure 3. As the spring members 34 move downwardly the brace 49 and rods 50 are moved downwardly to compress the coil spring 52 and at the same time the slot 39 in the bracket 40 permits the fiat portions 38 of the spring members 34 to slid therein. As the rods 50 move downwardly, the contact 18 is pivoted into engagement with the contact 17 so that the circuit to the solenoid 30 is completed. As the circuit to the solenoid 30 is completed, the core 31 moves to thereby cause the arm 32 to move the contact 26 into engagement with the contact 28 so that the circuit to the pump motor 22 is completed. Thus, the static electricity will then be grounded or led from the spring members 34 down through the bar 47 and then through the ground rod 48 so that the static electricity will be safely conveyed away. At the same time the pump motor 22 will be actuated so that the gasoline can be loaded into thetank 45 on .the truck 44. Also,.if desired a switch can be used 1. permit manual control of .theflow of gasoline and such a switch may be positioned'between the Pump more; 2.2 and the fuel line or fillline.

' As soon as the truck 44 has been loaded or as soon as it drives away, the spring '52 will return the parts ,to the positionshownjin Figure 2 so that the contact 18 will move away from the contact 17 wherebythe solenoid 3% will permit ,theconltact 26 to open the circuit to the pump mo- .tor122 so that no fuel can be accidentally pumped therefrom.

"The spring '52 is compressed when a truck passes over the spring members 34. The size and shape of the parts be varied as desired. The housing 'may be made waterproofand explosion proof, and the switch 16 prevents the oil or gasoline or other petroleum products from flowing'into the tank truck 44 until the truck is properly grounded. ,If a tank truck is to be gravity filled, alsdlenoid valve or a motorized valve of adequate size can b installed in the ifill line or pipe leading from the storage tank .to the loading platform. With the present invention the truck is automatically grounded so that danger from fires and explosions is automatically prevented. The parts may be made of any suitable material, as for example'the bar'47 may be made of copper, and the rod '48 may be made of copper with a steel core. The outermost rods 50 serve as guide rods to help maintain the 'parts in their proper position as the spring members 34 flex. The present invention is especially suitable for use at petroleum refineries, warehouses, and storage plants or whereveroil or gasoline tank trucks pick up a load since the possibility of an explosion resulting from static electricity will be eliminated, and the present invention will prevent explosions at the loading platform whenever a tank truck arrives to be refilled. Thus, when a tank truck rolls up it is automatically grounded to thereby eliminate the human factor. 'Heretofore it has been necessary to have an employee whose sole function is to clamp some .kind of a ground onto tank trucks when they roll in to be loaded but with the present invention it is not necessary to have an employee standing by for this operation. The number of spring members 34 can be varied as desired. The knobs 43 will scrape along the bottom of the truck as the truck passes over, and the switch 16 will prevent gasoline or fuel oil or kerosene from being pumped out unless there is a proper and complete ground. Thus, the grounding rod 43 carries all of the static electricity safely down'into the ground. The bracket safely covers the ends of the'spr'ing members 34 which move so that there will be no possibility of any one getting hurt by the movement of these parts. The housing 15 may be positioned in a vault which can be. lined with concrete if desired. A suitable cover or door can be provided for gaining access to the housing 15. A coil spring 53 is connected to the movable contact 18.

It is to be understood that the motor 22 which starts the flow of oil or gasoline or other product from the pump may be some distance away from the pump itself so that the motor may be in the fuel pump or elsewhere, but it functions as though incorporated therein. The coil spring 52 serves to bring the middle rod back up thus carrying with it'the brace 49 and the end rod 50. As this happens, the spring members 34 also go back up to their normal position. The brace 49 is not secured to the spring members 34 but merely rests immediately beneath them and touches them. Since frequently personnel operating the various apparatus might permit the flow to keep going until the whole yard of a storage depot is flooded with: fuel oil or gasoline, the gasoline or other petroleum products may flow automatically, or else a switch can be installed between the pump motor 22 and the fuel line or fill line so as to permit manual control of the flow of c 4 gasoline. If desired only one spring member 34 may be used.

Iclaim:

1. In a static electricity discharge mechanism, a horizontally disposed plate, a hollow housing positioned below said plate, a switch positioned in said housing and including a fixed contact, a movable contact pivotally mounted in said switch and mounted for movement into and out of engagement with .said fixed contact, a first wire extending from said movable contact and adapted to be connected to a source of electricalenergy, a'second wire leading from said fixed contact, a base spaced from said plate, a fuel pump mounted on said base and including a motor, a'third wire leading from .said motor and adapted to be connected to a source of electrical energy, a fourth wir leading from said motor, a movable terminal having one end connected to said fourth wire and its other end mounted for movement into and out of engagement with a fifth wire, said fifth wire adapted to be connected to a source of electrical energy, a solenoid connected to said second wire and adapted to b connected to a source of electrical energy, a core movably mounted in said solenoid, an arm connecting said core to said movable terminal, a plurali-ty of spaced parallel 'springmernbers mountedabove said plate,'each 'of said spring members having one end secured to said'plate and each of said spring members further including an offset section and a major curved portion'terminating in a fiat section, a bar extending transversely below the offset sections of said spring members, a ground rod depending from said bar, a brace extending transversely beneath the curved portions of said spring members and above said plate, and a plurality of-spaced parallel arms depending from said brace and extending down through said plate, one of said arms having its lower end 'pivotally connected to the movable contact in said switch.

'2. Thestructure as defined in claim 1, and further including a plurality of spaced apart knobs extending upwardly from said spring members for engagement with a portion of atruck.

3. The structure as defined in claim 1, wherein said spring members are adapted to be flexed downwardly by the lower portion of a fuel truck to be filled with fuel.

4. In a static electricity discharge mechanism, a horizontally disposed plate, a hollow housing positioned below said 'plate, a switch positioned in said housing and including a .fixed'contact, a movable contact pivotally mounted in said switch and mounted for movement into and out of engagement with said fixed contact, a first wire extending from said movable contact and adapted to be connected to a source of electrical energy, a second wire leading from saidfixed contact, a base spaced from said plate, a fuel pump mounted on said base and including'a motor, a third wire leading from said motor and adapted-to be connected to a source of electrical energy, a fourth 'wire leading from said motor, a movable terminal having one end connected to said fourth wire and its other-end mounted for movement into and out of engagement with a fifth wire, said fifth wire adapted to be connected to a source of electrical energy, a solenoid connected to said second wire and adapted to be connected to a source of electrical energy, a core movably mounted in said'soleno'id, an arm connecting said core tosaid movable terminal, a plurality of spaced parallel spring members mounted above said plate, each of said spring members having one end secured to said plate and each of said spring members further including an offset section and a majorcurved portion terminating in a flat section, a bar extending transversely below the offset sections of said spring members, a ground rod depending from said bar, a brace extending transversely'beneath'the curved portions of said spring members and above said plate, a plurality of spaced parallel arms depending from said brace and extending down through said plate, one of said arms having its lower end pivotally connected to the movable contact in said switch, a plurality of knobs extending upwardly from said spring members, said spring members adapted to be fixed downwardly by engagement with the lower portion of a fuel truck being loaded, and a bracket secured to said plate and provided with slots for slidably receiving the flat portions of said spring members.

5. In a static electricity discharge mechanism, a plate, a housing positioned below said plate, a switch positioned in said housing and including a fixed contact, a movable contact pivotally mounted in said switch and mounted for movement into and out of engagement with said fixed contact, a first wire extending from said movable contact and adapted to be connected to a source of electrical energy, a second wire leading from said fixed contact, a base spaced from said plate, a fuel pump mounted on said base and including a motor, a third wire leading from said motor and adapted to be connected to a source of electrical energy, a fourth wire leading from said motor, a movable terminal having one end connected to said fourth wire and its other end mounted for movement into and out of engagement with a fifth wire, said fifth wire adapted to be connected to a source of electrical energy, a solenoid connected to said second wire and adapted to be connected to a source of electrical energy, a core movably mounted in said solenoid, means conmeeting said core to said movable terminal, a plurality of spring members mounted above said plate, each of said spring members having one end secured to said plate and each of said spring members further including an offset section and a major curved portion terminating in a flat section, a bar extending below the offset sections of said spring members, a ground rod depending from said bar, a brace extending beneath the curved portions of said spring members and above said plate, and a plurality of arms depending from said brace and extending down through said plate, one of said arms being pivotally connected to the movable contact in said switch.

References Cited in the file of this patent UNITED STATES PATENTS 985,977 Cook Mar. 7, 1911 1,539,740 Johnson May 26, 1925 1,836,058 Bancroft Dec. 15, 1.931 1,973,275 Babson Sept. 11, 1934 1,999,414 King Apr. 30, 1935 2,092,948 Baitinger Sept. 14, 1937 

